Kinetic parameters of PEPC of the single-cell functioning C4 species B. sinuspersici and S. aralocaspica and related chenopod species
Leaves were collected after 5 h into the light and 5 h into the dark period. Activity was assayed at pH 8.0. Values represent the mean of at least three independent determinations (ses are shown).
| Species | Photosynthetic Type | Parameter | Light | Dark |
|---|---|---|---|---|
| B. sinuspersici | Single-cell C4 | Apparent Vmax (units/mg protein) | 1.96 ± 0.01 | 1.78 ± 0.04 |
| Km (PEP) (mm) | 0.06 ± 0.01 | 0.06 ± 0.01 | ||
| S. aralocaspica | Single-cell C4 | Apparent Vmax (units/mg protein) | 1.67 ± 0.03 | 1.06 ± 0.04 |
| Km (PEP) (mm) | 0.10 ± 0.01 | 0.12 ± 0.02 | ||
| H. persicum | Kranz C4 | Apparent Vmax (units/mg protein) | 1.27 ± 0.04 | 0.87 ± 0.04 |
| Km (PEP) (mm) | 0.12 ± 0.03 | 0.17 ± 0.03 | ||
| S. eltonica | Kranz C4 | Apparent Vmax (units/mg protein) | 0.83 ± 0.03 | 0.67 ± 0.08 |
| Km (PEP) (mm) | 0.09 ± 0.02 | 0.10 ± 0.03 | ||
| S. richteri | Kranz C4 | Apparent Vmax (units/mg protein) | 0.93 ± 0.03 | 1.00 ± 0.04 |
| Km (PEP) (mm) | 0.21 ± 0.04 | 0.22 ± 0.04 | ||
| S. linifolia | C3 | Apparent Vmax (units/mg protein) | 0.09 ± 0.01 | 0.08 ± 0.01 |
| Km (PEP) (mm) | 0.05 ± 0.01 | 0.05 ± 0.01 |